Kamelbogenschütze (Civ4 FFH)
This units main advantage is that it is a mounted national unit that requires no resource.
Long accustomed to dodging abrupt sandstorms before the civilizations of Erebus stumbled upon them late in the Age of Rebirth, if a trained camel is matched with a capable rider they can virtually become the sandstorms themselves, arriving in a flurry and disappearing at a moments notice. Large Animal stables are required to produce and outfit this ungainly beasts, however.
Camel archers start with a high withdrawal chance and can get even higher with promotions. A Large Animal Stables is required to train them. A civilization can only have 3 at once.